Toilet cistern



FIG. 1 is a Top View showing our new design;

FIG. 2 is a Left Side View thereof;

FIG. 3 is a Front View thereof;

FIG. 4 is a Right View thereof;

FIG. 5 is a Back View thereof;

FIG. 6 is a Bottom View thereof; and,

FIG. 7 is an Isometric View thereof. 

The ornamental design for a toilet cistern, as shown and described. 